In the conventional technology, limitation to a bearing inner race at one side is typically implemented by providing a shaft shoulder on a shaft, and the technique of limitation to the bearing inner race at the other side mainly includes the following kinds. One kind is to provide a groove or screw threads on the shaft, and secure a position-limiting component via this groove or the screw threads, and then limit the bearing by the position-limiting component; another kind is to limit the bearing by an interference fit; the third kind is to limit the bearing by adhesion; and the fourth kind is to mount a shaft cap on a shaft end.
The position limiting implemented by the interference fit and the adhesion have low reliability. Providing the groove or the screw threads on the shaft to limit the bearing inner race may reduce the strength of the shaft, thereby affecting the performance and the operation safety of the entire mechanical equipment. The method of mounting a shaft cap on a shaft end is not applicable to a bearing mounted on a long shaft. For the bearing mounted on the long shaft, the long shaft is generally designed to be a tapered shape, and an end of the shaft far away from the load end generally has a small shaft diameter.